C+ pic gut's.

[tony777]

Do you feel that you have enough gain ?

whooo!!! very tempting

 

[Shep]

The filter cap board is pretty sturdy, so just heat the big blobs of solder and the caps should lift out.
Be sure to replace the black wire on the bottom as it takes B+ right off one of the caps. Don't forget the bias caps
while you are under there. A small tip, if you cannot turn the board over fully you may have to desolder the red lead going over the
board to the standby switch. Removed the two screws and plastic standoffs and you can flip it right over.

The main PCB traces are not that strong, so being easy with the iron will help. Almost all of the components are bend under the board to
hold them for soldering, so if a piece does not come out quick and easy, snip it.

Do you feel that you have enough gain ?

Thats a Pretty full on question. ahha
Um not sure right now i am wanting it to be nice and smooth with plenty and silk and sustain and compression so yes. I want to also use it as a low gain (dumble style ) Jazz fusion sort of stuff amp. what do you think???


Thanks Ed!!!!



Tom

 

[JOEY B.]

Not plenty of gain in the C+ lead channel???????? That is what the Xotic RC Booster is for. Turn the lead drive down and use the pedal for single note leads. 8) Dumble city with the right settings and the pedal off.

 

[chipaudette]

I LOVE CIRCUIT TALK!

This thread is right up my alley. I'm definitely into hearing about and discussing circuit mods. Can't get enough of it, in fact.

Thanks so much!

Chip

 

[Boogiebabies]

Not plenty of gain in the C+ lead channel???????? That is what the Xotic RC Booster is for. Turn the lead drive down and use the pedal for single note leads. 8) Dumble city with the right settings and the pedal off.

You can add gain, but you can also alter the lead voicing a bit if you want it a bit thicker and saturated, or add a midrange punch.

 

[Shep]

Not plenty of gain in the C+ lead channel???????? That is what the Xotic RC Booster is for. Turn the lead drive down and use the pedal for single note leads. 8) Dumble city with the right settings and the pedal off.

You can add gain, but you can also alter the lead voicing a bit if you want it a bit thicker and saturated, or add a midrange punch.

Yes please! That sounds great!

 

[Boogiebabies]

The V2A cathode is un-bypassed, so here is an opportunity for more gain.
In the circled area above, add a 10-25V bypass cap. It can be tantalum, Metallized Poly, and even electrolytic with the
negative toward the ground. The values can be tested with clipping the cap to the 1K5 resistor with test leads as it is
only a 2V or so circuit. Try a 2.2uf for a midrange boost or 10uf - 15uf for thicker gain. The result will be around
6db of boost. Use your ears to fine tune.
NOTE !!! THIS WILL ADD SOME BOOST TO THE CLEAN CHANNEL SO BE PREPARED TO ADJUST VOLUME 1.
If you are adventurous and only want a lead channel boost, you can piggy back another LDR on LDR 2 to switch it in on
only in lead mode, or if you have room for a switch, just solder the cap to the input of the circuit and the ground to the on off switch.

For even more gain do the mod above and then replace the buss wire from Volume 1 to the Treble pot with
a 100K 1/2W resistor. Carbon Comp, Carbon Film or Metal film are all fine, but you can decide what the type of resistors
does to your tone. 10uf-15uf caps add around 10-12db of fat boooooost !!!
NOTE !!! THIS MOD MAY CAUSE YOUR AMP TO BE A FIRE BREATHING DRAGON. EXPECT THE SAME GAIN AT 5 ON THE VOL. 1 WHERE 8
USED TO BE !!! THEREFORE VOLUME 1 CAN BE REALLY HOT AT 8....

NOTE !!! IF YOU ARE HAM FISTED, DO NOT SOLDER CAP TO THE HOLE IN THE V2A TRACE, USE THE MIDDLE OF THE TRACE OR SEE IF YOU CAN
PIGGY BACK IT ONTO THE RESISTOR. THE TRACES ON THESE BOARDS ARE THIN SO MOD AT YOUR OWN RISK. I TAKE NO RESPONSIBILITY FOR ANYTHING
BUT MORE GAIN !!!!

 

[Shep]

thanks ed that looks great. I think i and going to first off going to do one of the reductioning mod's. And put a 10uf off the v2 . I am wanting to not change the clean as much as possible so i think i will piggy back a ldr off ldr 2. But just wondering is that the closest ldr to that tube? Which one is ldr 2.i am wanting to get the smoothest lead out of it with the nicest clean. Do you reckon just those mod's will do it? Thank ed

Tom

 

[chipaudette]

Hi Boogiebabies,

Thanks for the awesome post about circuit mods. I followed you regarding the cathode bypass cap on V2A, and I followed you regarding the 100K between the Treble and Volume pots (though I'm surprised). After that, though, I lost you. You were talking about the 100K resistor and then, all of a sudden, you started talking talking about...

"10uf-15uf caps add around 10-12db of fat boooooost !!!"

Where are you talking about inserting this cap?

Chip

 

[av8or3]

For the life of me, I cannot imagine the need for more gain on these little amps. There is such a difference between my IIB and my C+ that I have uses for both of them. They're different animals. The C+ is just dripping with gain without pulling Bright switchs or cranking up the Presence. It's like I need a 30' cord just to stand far enough away. What do you guys do with more gain...?
Jim

 

[tony777]

What do you guys do with more gain...?

heavy metal :twisted:

 

[CoG]

What do you guys do with more gain...?
Jim

Buzz lots :lol:

 

[Boogiebabies]

Hi Boogiebabies,

Thanks for the awesome post about circuit mods. I followed you regarding the cathode bypass cap on V2A, and I followed you regarding the 100K between the Treble and Volume pots (though I'm surprised). After that, though, I lost you. You were talking about the 100K resistor and then, all of a sudden, you started talking talking about...

"10uf-15uf caps add around 10-12db of fat boooooost !!!"

Where are you talking about inserting this cap?

Chip

In the first photo of the mod reply, it's circled in red.

 

[Boogiebabies]

For the life of me, I cannot imagine the need for more gain on these little amps. There is such a difference between my IIB and my C+ that I have uses for both of them. They're different animals. The C+ is just dripping with gain without pulling Bright switchs or cranking up the Presence. It's like I need a 30' cord just to stand far enough away. What do you guys do with more gain...?
Jim

It's like horsepower. Too much is never enough...

It's not all about gain only, the mods add a little more thickness/roundness to the high and mid gain tones.
They also change the compression threshold. You can get a sweet thick, yet screaming tone earlier on the Vol. 1.

 

[silentrage]

hi Boogiebabies:
Someone in the IIIC+ thread recommended changing C27 to 20pf to reduce the brightness, this seems contrary to what you're recommending for the IIC+, could you tell me what I should actually do with the C27 in the III?

 

[Boogiebabies]

hi Boogiebabies:
Someone in the IIIC+ thread recommended changing C27 to 20pf to reduce the brightness, this seems contrary to what you're recommending for the IIC+, could you tell me what I should actually do with the C27 in the III?

10pf is the correct value for C27.

 

[merendina]

Great post Ed!!!

Boogiebabies Masterclass